This book addresses the synthesis of photosensitizers, the main emphasis being on the new methods of synthesis such as microwave, sonochemistry and the use of ionic liquids. It also addresses the photochemistry and photophysics of the photosensitizers alone and in combination with nanoparticles, the use of the photosensitizers in environmental control, safety and medicine. It discusses the common structures of the photosensitizers which are beneficial to these applications.